odourless solvents?

Some, like myself or 'er in doors', can't stand the smell of turps or white spirit so have to purchase the odourless varieties but what is the reason they are so expensive for the amount.

I've seen prices in excess of £24 for 1.89 litres of Bob Ross odourless artist thinners. All I can get at local diy store is low odour white spirit which doesn't help my problem. Hopefully someone can put my gripe to rest explaining why and there's me thinking vehicle fuel is a rip off by the Government
Many thanks for reading.